1. Field of the Invention
The present invention is directed to an electric shaver powered by rechargeable batteries, and more particularly to a self-contained electric shaver which is selectively energized from either of main or reserve rechargeable batteries and is further made water-tight to be utilized as a wet shaver.
2. Description of the Prior Art
There has been proposed an electric shaver incorporating main and reserve rechargeable batteries for the purpose of continuously energizing the shaver by the reserve battery when the main battery is exhausted, as taught from U.S. Pat. No. 3,108,192 which illustrates an electric circuit for selectively energizing an appliance operating mechanism from either a main rechargeable battery or a reserve rechargeable battery. However, the prior shaver incorporating the main and reserve batteries has no provision of a water-tight sealing and is therefore not utilized for a wet shave.
While on the other hand, an electric shaver capable of being used as a wet shaver incorporating a rechargeable battery is disclosed in U.S. Pat. No. 4,451,980 which includes the provision of an arrangement of discharging the gas produced upon charging of the battery out of a housing of the shaver while preventing the water from entering the interior of the housing. The above gas-discharging and water-tight sealing arrangement is rather complicated and therefore would be further increased its complexity when a reserve battery is additionally incorporated into the shaver, which would be the cause of increasing manufacturing costs and at the same time of lowering reliability. Consequently, it is mostly desired for a self-contained electric shaver with a pair of main and reserve rechargeable batteries to have a structural feature which satisfies both the water-tight sealing and the gas-discharging performance in a simple construction.